The present invention generally relates to flexible holding members that lock into a desired shape. More particularly, the present invention relates to flexible articulated arms useful for forceably holding an object against a surface, particularly an undulating surface.
Flexible arms that can be adjusted to a desired position or attitude and then xe2x80x9clockedxe2x80x9d into position serve a variety of uses in industry and in medicine. For example, such devices are useful for holding a light at a desirable angle or location, or for holding an object against a grinding wheel. However, in practice it is difficult to keep the flexible arm from moving after it has been xe2x80x9clockedxe2x80x9d into position if it is used to hold or support a heavy object or when used to forceably hold an object against a surface, particularly against an undulating surface.
When adapted for attachment to a stationary object, such as a chest retractor, a flexible arm can be used during surgery for holding a medical device in a desired location. It has proven particularly difficult to obtain a flexible arm that can be used in this fashion to position and hold a device, such as a suction body, against the undulating surface of a beating heart while applying sufficient pressure to the surface of the heart to stabilize an area on the surface of the heart for surgery. The constant movement of the undulating surface tends to break down the xe2x80x9csetxe2x80x9d of the arm, leading to eventual loss of rigidity and even collapse.
If the surgical site is on the anterior side of the heart (when the patient is lying on his back), it would be desirable to have a stabilizer arm long enough to attach and stabilize the suction device against the anterior side of the heart. However, in an articulated flexible arm of multiple links, the longer the arm, the harder it is to keep the arm rigid once it is in place and locked into position. Each jointure between two links in the articulated arm is a potential site of movement, and the greatest moment of movement is at the jointure of the flexible arm to the base used to mount the arm upon a stationary object. This difficulty is compounded when the surface against which the arm is to be placed is in constant movement, such as the surface of a beating heart.
Accordingly, there is still a need in the art for flexible holding members that lock into a desired shape. More particularly, there is still a need in the art for flexible articulated arms useful for forceably holding an object against a surface, particularly an undulating surface.
The present invention overcomes many of the problems in the art by providing stabilizer arm assemblies for forceably holding an object against a surface. The invention stabilizer arm assembly comprises a mounting assembly comprising a mounting base and moveable mounting clamp for removeably clamping the stabilizer arm assembly to a stationary fixture; a flexible arm attached to the mounting base, said flexible arm comprising multiple articulated elongate links with each link being rotatably joined to adjacent links; a turret joint comprising a freely rotatable socket attached to the distal-most link of the arm; a holding appendage fixedly joined to the turret joint; and a tightening mechanism loosely attaching together the mounting base, the multiple links of the arm, and the freely rotatable socket of the turret joint. Upon actuation of the tightening mechanism, the turret joint, the links of the arm and the mounting base are rigidly compressed together so as to hold the assembly in a fixed attitude while from about one to about twenty pounds of counter-force is applied against the appendage.
In another embodiment, the invention provides a stabilizer arm assembly comprising a mounting base; a flexible arm attached at the proximal end thereof to the mounting base, said flexible arm comprising a plurality of articulated links of graduated diminishing length from the proximal to the distal end thereof; a joining piece that enhances the friction in the jointure between the mounting base and the proximal-most link of the flexible arm; a turret joint comprising a freely rotatable socket, being attached to the distal-most link of the arm via the freely rotatable socket; an appendage fixedly attached to the turret joint; and a tightening mechanism loosely attaching together the mounting base, the joining piece, the plurality of links of the flexible arm, and the freely rotatable socket of the turret joint. Acutation of the tightening mechanism rigidly compresses together the turret joint, the links of the arm, the joining piece, and the mounting base so as to hold the assembly in a fixed attitude while from about one to about twenty pounds of counter-force is applied against the appendage and wherein the joining piece resists a greater force than the force at jointures between adjacent links of the arm.